#if (EXPR)
#if (EXPR) BLOCK
#if (EXPR) BLOCK else BLOCK
#if (EXPR) BLOCK elsif (EXPR) BLOCK ...
#if (EXPR) BLOCK elsif (EXPR) BLOCK ... else BLOCK
#STATEMENT if (EXPR)


print "Happy Birthday!\n" if ($date == $today);

if ($date == $today)
{
   print "Happy Birthday!\n";
}

if ($date == $today)
{
   print "Happy Birthday!\n";
}
else
{
   print "Happy Unbirthday!\n";
}



if ($date == $today)
{
   print "Happy Birthday!\n";
}
elsif ($date == $christmas)
{
   print "Happy Christmas!\n";
}



if ($date == $today)
{
   print "Happy Birthday!\n";
}
elsif ($date == $christmas)
{
   print "Happy Christmas!\n";
}else
{
   print "Happy Unbirthday!\n";
}


print "Happy Unbirthday!\n" unless ($date == $today);
#is equalent to
print "Happy Unbirthday!\n" if ($date != $today);


unless ($date != $today)
{
   print "Happy Unbirthday!\n";
}
else
{
   print "Happy Birthday!\n";
}


($date == $today) ? print "Happy B.Day!\n" : print "Happy Day!\n";